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1 parent eb820443
Showing 15 changed files with 40 additions and 23 deletions Show diff stats
common.py
common.pyc
msteg/StegBase.py
msteg/StegBase.pyc
msteg/steganalysis/ChiSquare.py
msteg/steganography/F3.py
msteg/steganography/F3.pyc
msteg/steganography/F4.py
msteg/steganography/F4.pyc
msteg/steganography/F5.pyc
msteg/steganography/LSB.py
msteg/steganography/LSB.pyc
msteg/steganography/StegBase.pyc
test_jpeg.py
test_steg.py
@@ -64,7 +64,8 @@ def bits2bytes(arry_bits):
     """
     str_bits = ''.join(map(str, arry_bits))
     arry_bytes = [int(str_bits[i:i + 8], 2) for i in range(0, len(str_bits), 8)]
-    return np.array(arry_bytes).ravel()
+    return np.array(arry_bytes,dtype=np.uint8).ravel()
+
  
  
 if __name__ == '__main__':
@@ -55,7 +55,7 @@ class StegBase(object):
         for i in xrange(4):
             raw[i] = raw_size % 256
             raw_size /= 256
-        self.hid_data = np.array(raw)
+        self.hid_data = np.array(raw, dtype=np.uint8)
  
         if np.size(self.hid_data) * 8 > np.size(self.cov_data):
             raise Exception("Cover image is too small to embed data.Cannot fit %d bits in %d DCT coefficients" % (
@@ -71,22 +71,28 @@ class StegBase(object):
         try:
             cov_data = self._get_cov_data(src_cover)
             hid_data = self._get_hid_data(src_hidden)
-            cov_data = self._raw_embed(cov_data, hid_data)
+            # print hid_data.dtype,type(hid_data),hid_data.tolist()
+            cov_data, bits_cnt = self._raw_embed(cov_data, hid_data)
+
+            if bits_cnt != np.size(hid_data) * 8:
+                raise Exception("Expected embedded size is %db but actually %db." % (
+                    np.size(hid_data) * 8, bits_cnt))
  
             self.cov_jpeg.setCoefBlocks(cov_data)
             self.cov_jpeg.Jwrite(tgt_stego)
  
-            size = os.path.getsize(tgt_stego)
+            # size_cov = os.path.getsize(tgt_stego)
+            size_cov = np.size(cov_data) / 8
             size_embedded = np.size(hid_data)
  
-            self._display_stats("embedded", size, size_embedded,
+            self._display_stats("embedded", size_cov, size_embedded,
                                 time.time() - self.t0)
  
         except TypeError as e:
             raise e
-        except Exception:
-            raise Exception(
-                'DCT coefficients exhausted. This usually means there are not enough DCT coefficients in the image in which algorithm can actually embed data. You should choose a larger image.')
+        except Exception as expt:
+            print "Exception when embedding!"
+            raise
  
     def _post_extract_actions(self, src_steg, tgt_hidden):
         """
@@ -95,11 +101,13 @@ class StegBase(object):
         """
         try:
             steg_data = self._get_cov_data(src_steg)
-            emb_size = os.path.getsize(src_steg)
+            # emb_size = os.path.getsize(src_steg)
+            emb_size = np.size(steg_data) / 8
+
  
             # recovering file size
             header_size = 4 * 8
-            size_data = self._raw_extract(steg_data, header_size)
+            size_data, bits_cnt = self._raw_extract(steg_data, header_size)
             size_data = bits2bytes(size_data)
             size_hd = 0
             for i in xrange(4):
@@ -110,15 +118,22 @@ class StegBase(object):
             if raw_size > np.size(steg_data):
                 raise Exception("Supposed secret data too large for stego image.")
  
-            hid_data = self._raw_extract(steg_data, raw_size)
+            hid_data, bits_cnt = self._raw_extract(steg_data, raw_size)
+
+            if bits_cnt != raw_size:
+                raise Exception("Expected embedded size is %db but actually %db." % (
+                    raw_size, bits_cnt))
+
             hid_data = bits2bytes(hid_data)
+            # print hid_data.dtype,type(hid_data),hid_data.tolist()
             hid_data[4:].tofile(tgt_hidden)
  
             self._display_stats("extracted", emb_size,
                                 np.size(hid_data),
                                 time.time() - self.t0)
-        except:
-            raise Exception('DCT coefficients exhausted.The stego image is probably corrupted.')
+        except Exception as expt:
+            print "Exception when extracting!"
+            raise
  
  
     def _looks_like_jpeg(self, path):
@@ -16,11 +16,12 @@ Better Steganalysis
 from collections import defaultdict
 import os
  
-import Image
+from PIL import Image
 import numpy
 from scipy.stats import chisquare
 import matplotlib.pyplot as plt
 import itertools as it
+from msteg.StegBase import StegBase
  
 from stegotool.util.plugins import describe_and_annotate
 from stegotool.util.plugins import ImagePath, NewFilePath
@@ -12,7 +12,7 @@ is embedded repeatedly in order to make non-ambiguous extraction possible.
 import time
 import math
 import numpy as np
-from StegBase import *
+from msteg.StegBase import StegBase
 from common import *
  
  
@@ -74,7 +74,7 @@ class F3(StegBase):
             i += 1
             if i == hid_data.size: break
  
-        return cov_data
+        return cov_data,i
  
     def _raw_extract(self, steg_data, num_bits):
         """
@@ -90,7 +90,7 @@ class F3(StegBase):
             hid_data[j] = x & 1
             j = j + 1
  
-        return hid_data
+        return hid_data,j
  
     def __str__(self):
         return 'F3'
@@ -9,11 +9,11 @@ which is not included in the original description of F4.
 """
 import time
 import numpy as np
-from StegBase import *
+from msteg.StegBase import StegBase
 from common import *
  
  
-class F3(StegBase):
+class F4(StegBase):
     """ This module has two methods: <i>embed_raw_data</i> to embed data
     with the F3 algorithm and <i>extract_raw_data</i> to extract data
     which was embedded previously. """
@@ -10,7 +10,7 @@ bits a parameter named word_size. Thus --- in this context --- word means
 import time
 import numpy as np
 import scipy as sp
-from StegBase import *
+from msteg.StegBase import StegBase
 from common import *
  
  
@@ -66,7 +66,7 @@ class LSB(StegBase):
             if x == 0 or x == 1 or cnt % 64 == 0: continue
  
             m = (hid_data[i] & 1)
-            x[...] = (x & 0xfffffffe) | m
+            x[...] = (x & 0xfffffffe) | m  # '0xfffe' is enough, for elements are expected to be short integers.
             i += 1
             if i == hid_data.size: break
  
@@ -186,7 +186,7 @@ if __name__ == &#39;__main__&#39;:
  
     ima = jpegObj.Jpeg("res/test3.jpg")
     imb = jpegObj.Jpeg("res/steged.jpg")
-
+    print ima.Jgetcompdim(0)
     diffblocks(ima, imb)
  
     c1 = ima.getCoefBlocks()
@@ -7,7 +7,7 @@ import pylab as plt
 import mjpeg
 import mjsteg
 import jpegObj
-from  msteg.steganography import F3
+from  msteg.steganography import F3, F4, LSB
 from common import *
...	...	@@ -64,7 +64,8 @@ def bits2bytes(arry_bits):
64	64	"""
65	65	str_bits = ''.join(map(str, arry_bits))
66	66	arry_bytes = [int(str_bits[i:i + 8], 2) for i in range(0, len(str_bits), 8)]
67		- return np.array(arry_bytes).ravel()
	67	+ return np.array(arry_bytes,dtype=np.uint8).ravel()
	68	+
68	69
69	70
70	71	if __name__ == '__main__':
...	...
...	...	@@ -55,7 +55,7 @@ class StegBase(object):
55	55	for i in xrange(4):
56	56	raw[i] = raw_size % 256
57	57	raw_size /= 256
58		- self.hid_data = np.array(raw)
	58	+ self.hid_data = np.array(raw, dtype=np.uint8)
59	59
60	60	if np.size(self.hid_data) * 8 > np.size(self.cov_data):
61	61	raise Exception("Cover image is too small to embed data.Cannot fit %d bits in %d DCT coefficients" % (
...	...	@@ -71,22 +71,28 @@ class StegBase(object):
71	71	try:
72	72	cov_data = self._get_cov_data(src_cover)
73	73	hid_data = self._get_hid_data(src_hidden)
74		- cov_data = self._raw_embed(cov_data, hid_data)
	74	+ # print hid_data.dtype,type(hid_data),hid_data.tolist()
	75	+ cov_data, bits_cnt = self._raw_embed(cov_data, hid_data)
	76	+
	77	+ if bits_cnt != np.size(hid_data) * 8:
	78	+ raise Exception("Expected embedded size is %db but actually %db." % (
	79	+ np.size(hid_data) * 8, bits_cnt))
75	80
76	81	self.cov_jpeg.setCoefBlocks(cov_data)
77	82	self.cov_jpeg.Jwrite(tgt_stego)
78	83
79		- size = os.path.getsize(tgt_stego)
	84	+ # size_cov = os.path.getsize(tgt_stego)
	85	+ size_cov = np.size(cov_data) / 8
80	86	size_embedded = np.size(hid_data)
81	87
82		- self._display_stats("embedded", size, size_embedded,
	88	+ self._display_stats("embedded", size_cov, size_embedded,
83	89	time.time() - self.t0)
84	90
85	91	except TypeError as e:
86	92	raise e
87		- except Exception:
88		- raise Exception(
89		- 'DCT coefficients exhausted. This usually means there are not enough DCT coefficients in the image in which algorithm can actually embed data. You should choose a larger image.')
	93	+ except Exception as expt:
	94	+ print "Exception when embedding!"
	95	+ raise
90	96
91	97	def _post_extract_actions(self, src_steg, tgt_hidden):
92	98	"""
...	...	@@ -95,11 +101,13 @@ class StegBase(object):
95	101	"""
96	102	try:
97	103	steg_data = self._get_cov_data(src_steg)
98		- emb_size = os.path.getsize(src_steg)
	104	+ # emb_size = os.path.getsize(src_steg)
	105	+ emb_size = np.size(steg_data) / 8
	106	+
99	107
100	108	# recovering file size
101	109	header_size = 4 * 8
102		- size_data = self._raw_extract(steg_data, header_size)
	110	+ size_data, bits_cnt = self._raw_extract(steg_data, header_size)
103	111	size_data = bits2bytes(size_data)
104	112	size_hd = 0
105	113	for i in xrange(4):
...	...	@@ -110,15 +118,22 @@ class StegBase(object):
110	118	if raw_size > np.size(steg_data):
111	119	raise Exception("Supposed secret data too large for stego image.")
112	120
113		- hid_data = self._raw_extract(steg_data, raw_size)
	121	+ hid_data, bits_cnt = self._raw_extract(steg_data, raw_size)
	122	+
	123	+ if bits_cnt != raw_size:
	124	+ raise Exception("Expected embedded size is %db but actually %db." % (
	125	+ raw_size, bits_cnt))
	126	+
114	127	hid_data = bits2bytes(hid_data)
	128	+ # print hid_data.dtype,type(hid_data),hid_data.tolist()
115	129	hid_data[4:].tofile(tgt_hidden)
116	130
117	131	self._display_stats("extracted", emb_size,
118	132	np.size(hid_data),
119	133	time.time() - self.t0)
120		- except:
121		- raise Exception('DCT coefficients exhausted.The stego image is probably corrupted.')
	134	+ except Exception as expt:
	135	+ print "Exception when extracting!"
	136	+ raise
122	137
123	138
124	139	def _looks_like_jpeg(self, path):
...	...
...	...	@@ -16,11 +16,12 @@ Better Steganalysis
16	16	from collections import defaultdict
17	17	import os
18	18
19		-import Image
	19	+from PIL import Image
20	20	import numpy
21	21	from scipy.stats import chisquare
22	22	import matplotlib.pyplot as plt
23	23	import itertools as it
	24	+from msteg.StegBase import StegBase
24	25
25	26	from stegotool.util.plugins import describe_and_annotate
26	27	from stegotool.util.plugins import ImagePath, NewFilePath
...	...
...	...	@@ -12,7 +12,7 @@ is embedded repeatedly in order to make non-ambiguous extraction possible.
12	12	import time
13	13	import math
14	14	import numpy as np
15		-from StegBase import *
	15	+from msteg.StegBase import StegBase
16	16	from common import *
17	17
18	18
...	...	@@ -74,7 +74,7 @@ class F3(StegBase):
74	74	i += 1
75	75	if i == hid_data.size: break
76	76
77		- return cov_data
	77	+ return cov_data,i
78	78
79	79	def _raw_extract(self, steg_data, num_bits):
80	80	"""
...	...	@@ -90,7 +90,7 @@ class F3(StegBase):
90	90	hid_data[j] = x & 1
91	91	j = j + 1
92	92
93		- return hid_data
	93	+ return hid_data,j
94	94
95	95	def __str__(self):
96	96	return 'F3'
...	...
...	...	@@ -9,11 +9,11 @@ which is not included in the original description of F4.
9	9	"""
10	10	import time
11	11	import numpy as np
12		-from StegBase import *
	12	+from msteg.StegBase import StegBase
13	13	from common import *
14	14
15	15
16		-class F3(StegBase):
	16	+class F4(StegBase):
17	17	""" This module has two methods: <i>embed_raw_data</i> to embed data
18	18	with the F3 algorithm and <i>extract_raw_data</i> to extract data
19	19	which was embedded previously. """
...	...
...	...	@@ -10,7 +10,7 @@ bits a parameter named word_size. Thus --- in this context --- word means
10	10	import time
11	11	import numpy as np
12	12	import scipy as sp
13		-from StegBase import *
	13	+from msteg.StegBase import StegBase
14	14	from common import *
15	15
16	16
...	...	@@ -66,7 +66,7 @@ class LSB(StegBase):
66	66	if x == 0 or x == 1 or cnt % 64 == 0: continue
67	67
68	68	m = (hid_data[i] & 1)
69		- x[...] = (x & 0xfffffffe) \| m
	69	+ x[...] = (x & 0xfffffffe) \| m # '0xfffe' is enough, for elements are expected to be short integers.
70	70	i += 1
71	71	if i == hid_data.size: break
72	72
...	...
...	...	@@ -186,7 +186,7 @@ if __name__ == '__main__':
186	186
187	187	ima = jpegObj.Jpeg("res/test3.jpg")
188	188	imb = jpegObj.Jpeg("res/steged.jpg")
189		-
	189	+ print ima.Jgetcompdim(0)
190	190	diffblocks(ima, imb)
191	191
192	192	c1 = ima.getCoefBlocks()
...	...
...	...	@@ -7,7 +7,7 @@ import pylab as plt
7	7	import mjpeg
8	8	import mjsteg
9	9	import jpegObj
10		-from msteg.steganography import F3
	10	+from msteg.steganography import F3, F4, LSB
11	11	from common import *
12	12
13	13
...	...